You might find this interesting: I have some carbs from a Chrysler 150 hp FIVE cylinder motor. They used THREE carbs: the top and bottom supply two cylinders each, with the center SIMILAR carb supplying that cylinder alone. Main jets in the top and bottom carbs were # 94s, where the center carb had a # 74.

You may recall the discussion we had on gas vapor clouds forming in front of one carb per cylinder motor at certain speeds. The top and bottom carbs on this Chrysler had overlapping suction pulses from the pair of cylinders that kept the vapor cloud in check, but not so that center carb! The airflow made multiple trips before finally getting into the motor, each time picking up a bit more fuel. Hence the need for a significantly leaner jet.

Jeff